The Copenhagen R3327 prostatic adenocarcinoma is an appropriate animal model of prostatic cancer. A major emphasis of this proposal will be to further characterize the response of these tumors to radiation and hormone therapy. The efficacy of treatment will be judged by changes in tumor size. A radioimmunoassay of rat prostatic acid phosphatase is being developed and its usefulness in detecting metastasis and following response to treatment will be determined. An in vitro clonogenic assay will be employed to determine the response to treatment of the prostatic tumor following either in vivo or in vitro therapy. Our findings of cytosol receptors for estrogen and progesterone have prompted us to assay the tumor's response to hormone treatments in addition to those related to androgen deprivation. The effects of combination hormone therapy will be studied. The nature of the steroid receptor population will be characterized with charcoal adsorption and sucrose density gradient analysis during this investigation. Metastases were found in androgen deprived animals but not in androgen maintained animals. We will investigate the role of steroidal hormones in metastasis and establish a metastatic tumor line. In addition to steroidal hormones, the anti-metastatic compound ICRF-159 will be evaluated for efficacy in preventing metastasis. The proteolytic activities of plasminogen activator, collagenase, and cathepsin B-1 will be related to the metastatic response of these tumors. Serum acid phosphatase and sialyltransferase activities will be determined and related to tumor metastasis. The effect of single and fractionated doses of irradiation on the tumor will be determined by histologic examination, tumor size, clonogenic assay, metastasis, and tumor progression.